1. Field of the Invention
The present invention relates to a lens assembly, and more particularly, to a lens assembly in which a lens is fixed via adhesion.
2. Descriptions of the Related Art
With the continuous advancement of optical technologies, corresponding electronic products such as projection apparatuses and digital cameras have found wide application in people's daily life in recent years. To fulfill users' demands for good portability and high pixel performance and imaging quality of these electronic products, the development of miniaturized photographic lenses and projection lenses becomes more and more important.
FIG. 1 illustrates a schematic cross-sectional view of a lens assembly of the prior art 1. The lens assembly 1 comprises a first lens 11, a second lens 12, a third lens 13, a frame 14 and a circular fixing element 15. The frame 14 is adapted to define a receiving portion 141 for receiving the third lens 13, the second lens 12 and the first lens 11 therein in sequence. Then, by having the circular fixing element 15 disposed on the first lens 11 and further fastened to the frame 14, the first lens 11, the second lens 12 and the third lens 13 are fixed into the frame 14. However, in the lens assembly of the prior art 1, the method in which the lenses are fixed are disadvantageous for the following two reasons. First, when the first lens 1 has a large outer diameter and a large curvature, the frame 14 must be made to have a large outer diameter, and the circular fixing element 15 and the frame 14 must be further made to have a large wall thickness to enhance the strength of fixing the first lens 11; consequently, this leads to an increased volume of the lens assembly 1. Second, when the circular fixing element 15 is further fastened to the frame 14 by means of the periphery of the first lens 11, the first lens 11 will receive both a pressure applied by the circular fixing element 15 and a reaction force applied by the frame 14 when the first lens 11 is pressed against the frame 14, which tends to cause flexure or deformation of the first lens 11 due to an overdue stress.
In view of this, an urgent need exists in the art to provide a lens assembly with a small volume that is capable of appropriately fixing a lens without deformation.